Charlie Munger hit upon one strategy when he was a young lawyer. He decided that whenever his legal work was not as intellectually stimulating as he’d like, “I would sell the best hour of the day to myself.” He would take otherwise billable time at the peak of his day and dedicate it to his own thinking and learning. “And only after improving my mind — only after I’d used my best hour improving myself — would I sell my time to my professional clients.”

Irrespective of how well you were able to get on with your day after that most recent night without sleep, it is unlikely that you felt especially upbeat and joyous about the world. Your more-negative-than-usual perspective will have resulted from a generalized low mood, which is a normal consequence of being overtired. More important that just the mood, this mind-set is often accompanied by decreases in willingness to think and act proactively, control impulses, feel positive about yourself, empathize with others, and generally use emotional intelligence.

In fact, some people’s emotions are so disturbed after a night of sleep deprivation that they could be classified as psychopaths.

That might make you into a good real ninja but not a productivity ninja. Wrong ninja.

All of these things combine to change the way they score on clinical mood disorder scales, often tipping perfectly normal people over the edge into the clinically relevant zone, so that, if tested on that particular day, they could be classified as depressed or even as psychopaths.

(There was) a school in New Haven that was located next to a noisy railroad line. To measure the impact of this noise on academic performance, two researchers noted that only one side of the school faced the tracks, so the students in classrooms on that side were particularly exposed to the noise but were otherwise similar to their fellow students. They found a striking difference between the two sides of the school. Sixth graders on the train side were a full year behind their counterparts on the quieter side. Further evidence came when the city, prompted by this study, installed noise pads. The researchers found this erased the difference: now students on both sides of the building performed at the same level.

Habits emerge from the gradual learning of associations between an action and outcome, and the contexts that have been associated with them. Once the habit is formed, various elements from the context can serve as a cue to activate the behavior, independent of intention and absent of a particular goal… Very often, the conscious mind never gets engaged.

The research of psychologists Amy Wrzesniewski and Jane Dutton shows just how much of our mind-set — what we choose to focus on — affects our experience of work. Wrzesniewski and Dutton followed a group of hospital cleaners, and found that some of the cleaners experienced their work as a job — as something they did solely for the paycheck — and described it as boring and meaningless. But another group perceived the same work as a calling — and experienced the hours they spent at work as engaging and meaningful. This second group of hospital cleaners did things differently from the first group. They engaged in more interactions with nurses, patients, and visitors, taking it upon themselves to make everyone they came in contact with feel better. Generally, they saw their work in its broader context: They were not merely cleaning the wards and removing the trash, but were contributing to the health of patients and the smooth functioning of the hospital.

How do you do this? It’s about interacting with the people who experience the benefits of your work.

Wharton professor Adam Grant did research trying to motivate employees at a university call center.

When call center workers were shown letters written by grateful students who had received scholarships funded by the workers’ calls, their motivation soared.

What pushed their motivation even higher? Speaking with those students.

When callers interacted with one scholarship recipient in person, they were even more energized. The average caller doubled in calls per hour and minutes on the phone per week. By working harder the callers reached more alumni, resulting in 144 percent more alumni donating each week. Even more strikingly, revenue quintupled: callers averaged $412 before meeting the scholarship recipient and more than $2000 afterward.